Camilo Chiang and Günter Hoch publish two new papers on light responses in plants

Camilo recently defended his PhD in the PPE group, and has now published two new papers on his research.

The first paper investigated the effects of different light wavelength combinations in phytotrons (indoor growth chambers) on plant growth and physiology with the goal of achieving near to natural-like plant performance in indoor experiments. The experimental set up made use of seven different plant species from different plant functional types (herbs, grasses, and trees), and compared the growth responses against results from a field trial with the same species. The exposure to different blue light percentages induced species-specific dose response reactions for most of the analyzed parameters. Compared with intermediate blue light treatments (25% and/or 35% blue light), extreme red or blue light enriched treatments (6% and 62% of blue, respectively) significantly affected the height, biomass, biomass allocation, chlorophyll content, and photosynthesis parameters differently among species. Principal component analyses (PCA) confirmed that 6% and 62% blue light quality combinations induce more extreme plant performance in most cases, indicating that light quality needs to be adjusted to mitigate unnatural plant responses under indoor conditions.

The second paper used a similar methodology to evaluate how differences in the patterns of daily light, temperature, and humidity fluctuations influenced the capacity to achieve near to natural-like plant performance in the same phytotron facility. Three different climate regimes of increasing complexity were used: 1) constant daytime and nighttime conditions, 2) daily sinusoidal changes, and 3) variable conditions tracking the exact meteorological conditions from the field trials. Results from this work showed that the variable condition yielded lower biomass compared to the fixed and sinusoidal conditions, as well as higher specific leaf area and chlorophyll concentrations. A principal component analysis (PCA) across all plant traits in response to climatic conditions suggested that sinusoidal fluctuation is recommended for a more natural-like plant performance in indoor growth facilities. However, significant differences for several traits between field- and indoor-grown plants even under variable climates indicate that additional factors can bias plant performance in indoor facilities beyond those that can be controlled in standard phytotrons, such as wind speed and direction, and leaf and soil temperature.

Links to both publications: